MiniUPnP Documentation

Anywhere I can find the MiniUPnP documentation ?

For example, some documents describe the parameters of this function.

LIBSPEC int
UPNP_AddPortMapping(const char * controlURL, const char * servicetype,
                    const char * extPort,
                    const char * inPort,
                    const char * inClient,
                    const char * desc,
                    const char * proto,
                    const char * remoteHost,
                    const char * leaseDuration);